redhead



April 21, 1959 E. B. REDHEAD MOLD FORMING APPARATUS 2 sheets-sheet 1'Filed oct. 17, 1957 t .il

FIG. 2.

ATTORNEY.`

E. B. REDHEAD MOLD FORMING APPARATUS April 21, 1959 2 Sheets-Sheet 2Filed Oct v2|."l., 1957 INVENTOR EDWARD BEAL REDHEAD ATTORNEY.

United States Patent() This invention relates to a method of andapparatus for introducing sand, powder or other free-ilowing materialupwardly into an open-bottomed receptacle such as a mold, ask, tank orbag, for the purpose of either fully or partially lling the receptacleand then compacting the material, generally, but not necessarily, into adense mass.

For the purpose of illustrating a typical practical application of thismethod, the description contained in this specification applies to afoundry molding machine for the making of green sand molds. It isrecognized, however, that this method can be adapted for use in othermolding practices such as core making and shell molding, as we'll as inunrelated fields wherein upward injection of free ilowing materialswould prove advantageous over conventional gravity feed or otherdownward flow methods.

The illustrated form of the invention pertains to the making of sandmolds used in metal casting procedures. The sand is molded in iiasks toform a cope and a drag,

' which will then be placed together to form the complete mold. In theformation of these sand molds patterns are used, and the sand is pressedunder high pressure against these patterns to form the desired contours.

Speaking generally, there are two methods of applying pressure to thesand. One involves the use of a fixed platen and a movable ram. Thepattern is usually mounted on the ram, and a flask encloses it on allsides. Sand is then deposited into the flask and onto the pattern, andthe ram then elevates both the pattern and ask in the direction of theplaten. The sand is thereby squeezed between the pattern and the platen,and a sand mold is thereby produced.

In the second method, the pattern and flask rest upon a platen or upon aram, and sand is deposited into the ask and upon the pattern in theusual way. Above the pattern and flask is a diaphragm head, and airunder high pressure is introduced into the diaphragm. This causes thediaphragm to press downwardly upon the sand and to squeeze it againstthe pattern, thereby producing a sand mold.

The present invention constitutes an improvement over the second methodabove described. It involves a reversal of parts and procedures toproduce a most unconventional machine and process, resulting in verysubstantial advantages over the prior art.

Specifically, the instant invention requires that the pattern be placedabove the sand, rather than below it as is conventional procedure in allcases. The present invention also requires that the diaphragm also beplaced below the sand and not above it. Furthermore, instead ofdepositing the sand into the ask, the sand is deposited into thediaphragm, which functions in the manner of a pouch prior to the moldingoperation herein described.

More specifically, the pattern in the present machine is secured to anoverhead pattern plate or platen. A conveyor carries the individualflasks to operative position immediately below the pattern, and a ram orelevator then elevates the liasks into engagement with thepatternsupporting platen. The iiask is now in operative position readyto receive a charge of sand.

The diaphragm is situated in a carriage which is movable into a positionbelow the sand hopper and from there into position directly below thepattern. The carriage is moved into position below the sand hopper, anda charge of sand is deposited into the diaphragm. The carriage is thenmoved into its second position, which is below the pattern, and airunder high pressure is introduced between the carriage and thediaphragm. This causes elevation of the diaphragm and its sand contentsand causes the sand to be injected into the ask. The diaphragm nowserves as the door of the ask, and

. further air pressure upon it causes it to squeeze the sand against thepattern, thereby producing a sand mold.

There are important advantages in this procedure, not the least of whichis the favorable positioning of the flasks. In all current methods ofsand molding, the im pression of the pattern in the sand is on theunderside of the ask and therefore not visible. In the present case, onthe other hand, the impression of the pattern in the sand is in the topof the ask and therefore readily inspected. Also, in current methods, adrag mold with exceptionally long sand projections below the face of themold, needs to be rotated degrees with the pattern remaining in itbefore the pattern can be drawn from the mold; otherwise, without thepattern remaining in the mold, there would be a strong likelihood thatthe long sand projections would break off, when the drag mold is rotatedthe original 180 degrees necessary for placing it in proper position toreceive the cope mold. In the present case, the drag mold does not needto be rotated either with or without the pattern in it, as the face ofthe mold is on the top side of the flask and therefore is already in theproper position to receive the cope mold. Also, in current methods, theintroduction of sand into the flask and the subsequent squeezing of thesand are divided into two separate operations. In the present case,however, the injecting and squeezing of the sand are combined into asingle operation, thereby substantially reducing the length of timerequired inthe making of a mold. Also, injecting the sand into the askat high speed as in the present case results in a mold of greater sandhardness than in current methods.

The invention is illustrated in the accompanying drawing, in which:

Fig. l is a side elevation of a machine made in accordance with thisinvention, parts thereof being shown in section to disclose innerfeatures that would otherwise not be seen.

Fig. 2 is a view of the same machine looking in the direction of arrows2, 2 in Fig. 1, the view in Fig. 2 being partly in vertical section.

Fig. 3 is a vertical section through the ask and pattern and through oneform of diaphragm construction.

Fig. 4 is a similar section showing the diaphragm in elevated position,pressing the sand against the pattern in the iiask.

Fig. 5 is a sectional view through another form of diaphragmconstruction.

Fig. 6 is still another section through still another form of diaphragm.

Fig. 7 is still another section through a further modification of thediaphragm construction.

Fig. 8 is a further section through another modification of thediaphragm construction, showing the use of a double diaphragm.

Referring now to Figs. 1, 2 and 3 of the drawing, it will be noted thatthe sand molding machine shown therein includes a base and a frame 12supported thereby. The frame supports a cross-head 14, which is xed inposition relative to the frame and the base. Secured to said cross-headis a stationary platen 16, and mounted on said platen is a pattern plate18. The pattern 2,0 is mounted on said pattern plate.

It will be observed that a conveyor 22 is situated on one side of themachine and that a second conveyor 24 is situated on the opposite sideof the machine, on the same level. These two conveyors include aplurality of rollers 26, which are adapted to support a ask or a seriesof asks 28. Conveyor 22 is the roll-in conveyor by which flasks aremoved into the machine. roll-out conveyor which removes the flasks fromthe machine.

`It will now be seen that each iiask 28 is provided with a bottom flange30 and a top flange 342. Rollers 26 of conveyors 22 and 24 are adaptedto support the top flange 32 ofthe asks and to carry the flask at alevel which would enable the flask to clear pattern on pattern plate 18.

' Supported by base 10 is an elevator 34, mounted on a pair of plungers36 and 3S, respectively. Hydraulic or pneumatic means, including lines40 and 42, elevate and lower the elevator to the extent necessary. Atthe top of the elevator is a pair of frame members 44 and 46, whichsupport two series of rollers 48. As the drawing clearly shows, theserollers are adapted to engage and support the upper flange 32 of theflask. In the operation of this part of the machine, a particular ask ismoved on conveyor 22 into the machine, and particularly with its upperflange 32 riding upon rollers 48. These rollers now support the tiaskbelow the pattern, and the elevator is caused to rise in order toelevate the flask to bring its upper flange 32 into abutment with thepattern plate 18. Pins 49 in the pattern plate 1.8 engage holes 51 inthe upper flange 32, and thereby position the ask. The iiasky is now inoperative position, ready to receive a charge of sand. At the conclusionof the molding operation shortly to be described, the elevator is causedto descend in order to enable the ask to clear the pattern, and the askis then rolled off rollers 26 of conveyor 24. The ask is now ready to beused in a casting operation.

Base 10 supports a pair of tracks 50 and 52, respectively, which runparallel to each other and at right angles to the path of movement ofthe flasks on conveyors 22 and 24. These tracks extend outwardly fromthe machine, at least on one side thereof, and at their far ends theyare supported on frame members 54. It will now be seen that tracks 50and 52 are adapted to support carriage 56. Carriage 56 comprises ahollow body portion 58 and frame. members 60 supporting said hollow bodyon a plurality of wheels 62. These wheels ride on tracks 50 and 52 abovementioned.

Body portion 58 has the shape of a fiask or container with four sidewalls and a bottom wall. It is open only atthe top. Along its upper edgeis an outwardly projecting ange 64. This flange extends along the entireperiphery ofthe body portion 58 and it supports the peripheral edge of aiiexible diaphragm 66. A frame 68 is disposed upon said peripheral edgeof the diaphragm, and screws 70 secure said frame 68 to said flange 64,to clamp the peripheral edge of the diaphragm between them.

The diaphragm 66 is made of flexible sheet material which may also beelastic. For example, natural or synthetic rubber would be a suitablematerial for this purpose. The relaxed condition of the diaphragm may beas shown in Fig. 3, wherein it assumes the shape of a pouch whose bottomwall rests on the floor of body inember 58. The diaphragm is thusadapted to receive a charge of sand 72 from an overhead sand hopper 74.It

will be noted that the hopper is situated oi to the side of' the machineproper and above an outwardly extending portion of tracks 50 and 52.

With the pouch thus filled with a charge of sand, the

Conveyor 24 is the carriage is moved into the machine as shown in Fig. 2of the drawing. The operative position of the carriage is immediatelyand directly below ask 28. Frame member 68 of the carriage virtuallyabuts the lower ange of the flask. The machine is now ready for the sandmolding operation.

It will now be noted that atiexible hose 76 is connected to a fitting 7Ssecured to the bottom wall of body 58 of the carriage, and that saidfitting isftubular to provide communication withl the inside of saidbody 5,8 between its inner wall and the diaphragm 66.` This hose 76 is acompressed air line which is connected in conventional manner to asource of air under high pressure. When the carriage is in its operativepositionimmediately below the flask, air is introduced through said hoseinto body 5S, and the diaphragm is forced upwardly together with itsload of sand. The air pressure is considerable,

y and the sand is thereby squeezed into the tiask and against thepattern. This Yconstitutes the molding operation, and the result isshown in Fig. 4. 4

The air is now permitted to escape from body 58, and the diaphragm isthereby permitted to fall to its inoperative position, as shown in Fig.3. The sand, however, remains lirm in the ask and, although the flasknow has no bottom wall, the sand remains in place nonetheless. The saidmold is now completed and the carriage 58 may now be moved away.

The next step is to remove the flask with its sand mold contents fromthe machine and `to a place of use. This is accomplished by lowering theelevator 34 until the upper ange 32 of the ask is level with conveyor24, and the flask may then be rolled oi'rollers 48 of the elevator andonto rollers 26 of saidconveyor. The operation is now complete, and thesand mold ready for use.

Turning now to Fig. 5, it will be observed that a band 80 is insertedinto diaphragm 66 slightly below ange 64 of the body member 58. Thisband is xed in place to prevent upward movement of the upper peripheralportion of the diaphragm. The object of this band is to limit theoperative portion of the diaphragm to that portion which is disposedbelow the band.

Fig. 6 shows a variation of the arrangement in Fig. 5. In Fig. 6diaphragm 66a is shown to have its upper peripheral edge 661; curledaround a band or molding 80a. It is this band or molding which securesthe upper peripheral edge of the diaphragm to the inside of body member58 of the carriage. This is simply another way` of securing thediaphragm to the carriage and to provide an air-tight seal therebetween.

Fig. 7 shows a further variation wherein the sides of diaphragm 66C arefolded in accordion fashion to produce the pleats 66d shown -in thedrawing. The lowermost pleat is clamped in place against the floor ofbody portion 58` by means of a continuous bar 80b. The accordion featureof this diaphragm enables the diaphragm to rise readily under thepressure of the air.. l

Fig. 8 shows. another modification of this invention, wherein a doublediaphragm is used for the purpose of effecting greater uniformity in thedistribution of the sand in the flask and more-effective equalization ofthe compression of the sand. In addition to these advantages, the use ofa double diaphragm or, more precisely, a pair of diaphragms, enables theupper diaphragm to distribute itself more evenly across the open face ofthe ask. As shown in Fig. 8, air is introduced between the lowerdiaphragm 66e and the hollow body 58 of the carriage. Upward pressureupon the lower diaphragm 66e brings it into engagement with the upperdiaphragm 66j, which constitutes the pouch proper, and receives thesand. This upward pressure of the lower diaphragm elevates the upperdiaphragm to eject the sand into the flask` andto squeeze it against thepattern. The foregoing is illustrative of preferred fo'rmsofv thisinvention, and it will be understood that these preferred forms may bemodiedand other forms maybe'prov'ided' within the broad spread of theinvention and the broad scope of the claims.

I claim:

1. A sand molding machine comprising a base, a frame on said base, apattern plate supported at the top of said frame, a pattern supported bysaid pattern plate and projecting downwardly therefrom, means forpositioning a ask against said pattern plate, the ask projectingdownwardly from the pattern plate and forming an enclosure for thepattern, a receptacle which is closed at the sides and bottom and openat the top, means for positioning said receptacle immediately below theask, a diaphragm mounted in said receptacle and adapted to receive acharge of sand, and means for introducing air under pressure betweensaid diaphragm and said receptacle to elevate the diaphragm and therebyto inject the sand into the ask, the air pressure being suicient tosqueeze the sand against the pattern and thereby to form a sand mold,the means for positioning the ask against the pattern plate comprisingan elevator which elevates the ask from a position wherein the flask isadapted to clear the pattern to a position wherein the ask abuts theunderside of the pattern plate.

2. A sand molding machine comprising a base, a frame on said base, apattern plate supported at the top of said frame, a pattern supported bysaid pattern plate and projecting downwardly therefrom, means forpositioning a ask against said pattern plate, the ask projectingdownwardly from the pattern plate and forming an enclosure for thepattern, a receptacle which is closed at the sides and bottom and openat the top, means for positioning said receptacle immediately below theask, a diaphragm mounted in said receptacle and adapted to receive acharge of sand, and means for introducing air under pressure betweensaid diaphragm and said receptacle to elevate the diaphragm and therebyto inject the sand into the ask, the air pressure being suicient tosqueeze the sand against the pattern and thereby to form a sand mold,

the ask being provided with top and bottom flanges, a conveyor beingprovided for supporting the flask by means of its top ange, saidconveyor being situated on one side of the machine and at a relativelylow level to permit clearance by the ask of the pattern as it enters themachine, and a second conveyor situated at the opposite side of themachine in line with the first conveyor and on the same level therewith,whereby the flask may be removed from the machine following the sandmolding operation.

3. The combination of claim l, wherein the sand injecting diaphragm ispouch-shaped and open at the top, a support for said pouch-shapeddiaphragm, and air pressure means between said pouch-shaped diaphragmand said support therefor, said pouch-shaped diaphragm being adapted toreceive a charge of sand and said air pressure means being adapted toforce said pouch-shaped diaphragm upwardly in the direction of thepattern, to introduce the sand into the ask and to squeeze it againstthe pattern.

4. In a molding machine in accordance with claim 3, wherein a seconddiaphragm is disposed between the pouch-shaped diaphragm and the hollowbody, said second diaphragm being adapted to receive the pressure of theuid and to transmit it to the pouch-shaped diaphragm to elevate saidpouch-shaped diaphragm and thereby to eject its contents.

References Cited in the le of this patent UNITED STATES PATENTS1,804,181 Oyster May 5, 1931 2,588,669 Taccone Mar. 11, 1952 2,715,758Taccone Aug. 23, 1955 2,767,445 Taccone Oct. 23, 1956 FOREIGN PATENTS725,455 Great Britain Mar. 2, 1955

